1. Field of the Invention
The present invention relates to an improved device for ensuring automatic closure of pivoting doors and for holding them in open position.
In the following specification, the invention will be described for a device for ensuring automatic closure of a door which is opened manually, but it is obvious that this is not limiting and that such a device may possibly be motorized in order also to ensure automatic opening.
2. Prior Art
The most wide-spread device for ensuring automatic closure of a pivoting door is essentially constituted by a system of compasses with two legs, one being mounted to pivot on a box fixed on the door (or frame), the hinge pin being subjected to the action of a return means (spring system) and the end of the other leg being fixed, likewise in pivoting manner, on the frame (or door). Although such a device ensures automatic closure of the door, it nonetheless presents a certain number of drawbacks. In fact, taking into account their design, the compasses work over 90.degree., which brings about the creation of a considerable torque which, in the end, provokes wear of the hinge pins and even tear of the fixations. Moreover, it creates hard points during opening and, in general, it does not allow the door to be blocked in open position, which blocking must generally be effected via an additional element actuated by the foot, for example.
Various solutions have been proposed in order to overcome these drawbacks. For example, mention may be made of the solution proposed by French Patent Application published under No. 2 540 545 which relates to a device for automatically controlling opening of pivoting doors.
Such a device comprises:
a pivoting mechanism proper;
an arm adapted to be fixed by one of the ends to the rotating mechanism so that it may pivot in a plane;
a slide block mounted to pivot at the other end of the arm; and
a guide mechanism adapted to be fixed to the door and to the frame supporting said door in order to guide the slide block in a direction parallel to the plane.
Apart from the fact that this solution is complex and expensive to carry out, it also presents the drawback of not being able to block the door in open position. It presents further drawbacks such as the impossibility to operate it manually, a considerable torque due to the presence of compasses and a high resistance to opening.